Not able to validate the status IQ domain with a custom domain -Site24*7 or AWS-route 53 doesn't have any solution on this.

I have reached out to AWS and Site24*7 but both party not able to help on this due to which not able to use the status IQ pager after subscription.

https://serverfault.com/questions/834320/adding-both-cname-and-txt-dns-records-for-one-subdomain